dear community

I have 3 variables all measuring something for an extensive set fo countries.
One of them has a scale from 0 to 10. The other 2 are percentage rates. I would like to standardize the latter two to the former scale.
I have already generated the ratios of each (3 ratios) and generated the mean where one country has more than one observation,
f.e. an observation on 1 variable and an observation on another (same year same country).

Now I do not now how to adjust the ratios since I read only that I need to substract the mean and divide by the std,
however is that possible with the three ratios?

Hope that makes sense. Thanks in advance.